The present invention relates to inductive thin film magnetic read/write heads. In particular, the invention relates to an improved thin film head design which provides fewer erroneous output spikes due to "glitches" during the read back operation.
Thin film magnetic read/write heads are used for magnetically reading and writing information on a magnetic storage medium such as a magnetic disk which are in motion relative to one another. A thin film magnetic head comprises a pair of "yokes" or "paddles" which form the magnetic core of the head. Electrical conductors pass between the two paddles and are used for both reading and writing information on the magnetic storage medium. During a write operation, electrical current is caused to flow through the conductors which generates a magnetic field in the paddle. The structure includes a gap region which comprises a small space between the two tips of the two paddles. The write current in the coils causes magnetic flux to span the gap region. This magnetic flux is then used to impress a magnetic field upon a storage medium during the write operation which results in a magnetic transition being recorded. During the read operation the magnetic head and the storage medium also move relative to each other causing a changing magnetic field to be induced in the coil and the coils link the magnetic circuit. Electric signals in the conductors may be sensed with electric circuitry which allows recovery of information stored on the magnetic medium.
The performance of a thin film magnetic head is degraded by a phenomenon known as the "glitch" effect or "remote read" effect. The remote read effect is characterized by a voltage noise spike generated by the head in the coils after a random delay following completion of a write process. The voltage spike is of sufficient magnitude to be decoded as valid data which causes a system error. In prior art thin film magnetic heads, the glitch typically has a probability of occurring about once in every 10.sup.3 to 10.sup.5 write operations.
The occurrence of a glitch causes incorrect data to be read back from the magnetic medium and is highly undesirable. The prior art does not explain the interrelation of both design and material properties used in a thin film head on the remote read effect. An improved thin film head in which the glitch effect or remote read effect is statistically less likely would be a significant improvement to the art.